Miller, 42, was the global head of environmental and social risk management at New York-based Citigroup, America’s fourth largest bank.

Police believe Miller killed himself, Detective Martin Speechley, an NYPD spokesman, told Bloomberg News Wednesday. However, the official cause of death will remain a mystery until the autopsy report is concluded. Miller “was highly regarded at Citi and across the financial services industry as a leader and tireless advocate for environmental and sustainable business practices,” top managers at Citigroup wrote in a letter to staff in his department, Bloomberg reported.

“He will be greatly missed by all who knew him,” the letter said.

Investigators believe Miller killed himself after going on a drug, methamphetamine and alcohol bender, according to the Daily News, which said that cops found controlled substances in the apartment.

The banker was discovered by the building’s doorman on Tuesday afternoon, after his boyfriend was unable to get a hold of him. His body was found with a laceration to his neck, the NYPD said. He was pronounced dead by paramedics that arrived to the apartment.

On the night of his death he was reportedly keeping company with a man he met on Backpage.com, a classifieds site that is also used for sex solicitation.

Security video footage at his apartment complex shows that Miller had a confrontation in the elevator with an unidentified man late on Sunday night or early Monday morning. The Daily News said Miller called the doorman to ask the man not be let back into the building, and before his death, called 911 twice to complain about a ‘stalker’ outside the building.

Miller’s death comes on the heels of a wave of suicides and mysterious deaths in the financial sector in Europe and the US. Back in March, 28-year-old JP Morgan Chase investment banker,Kenneth Bellando’s body was found on a sidewalk after leaping to his death from his six-story Manhattan apartment building. Bellando was the twelfth person to commit suicide in the banking sector at the time of his death.

In April, Jan Peter Schmittmann a former exec at ABN AMRO, a large Dutch-based bank committed suicide after killing his wife and daughter. That same month the head of Bank Frick, a Liechtenstein based bank, exec was shot dead in a parking lot by Jürgen Hermann.

After the first batch of suicides early this year, Fortune Magazine wrote that banker suicides are not a new phenomenon. Clusters are known to occur whenever hardship strikes the industry, such as during the Great Depression or the Great Recession of a few years ago. In addition, sensationalistic reports of the deaths may lead to copycat fatalities.

According to the Centers for Disease Control and Prevention (CDC), bankers appear to be more prone to suicide than any other profession, barring “engineers and scientists.” For the years 1999, 2003, 2004 and 2007, there were 329 suicides among workers in the finance sector, Fortune reported.